The music video "Sober" by Big Bang may look fun and random. But it has some deep meaning and I really love this MV due to the meaning it has behind it.
Be aware that this is just my opinion, you might disagree with some of the things I say. But here we go:
The MV starts off with GD being in a green field with a bunch of beds. I see this as him building his own fantasy world in his mind. He's going crazy from all the dreams he has, it's like he's in an asylum.
The smoke he blows out of the smoke machine symbolizes a "dream" or "fantasy" like world.
Then it's Seungri. Those pieces of paper symbolize money. In this MV, he portrayed someone who is greedy and self obsessed. He wishes to buy everything he possibly could with the money he has. The lyrics of the song say: "If you only chase after money, power, & fame, your crotch is gonna rip and you're gonna fall."
Next you see Taeyang in this weird shower box thingy xD The box that he is in is full of steam, which represents him being stuck in his own fantasy world, & he is begging for somebody to let him out. He couldn't bear it.